Gamaliel came to Cesena Spinner as a refugee. His mother and brother were killed in a colony collapse in the L4 region. His father was killed several years later when his shuttle was attacked by pirates. These events left Gamaliel constantly aware of the fragility of life, and the importance of the Silver Knights' mission.
Gamaliel's sister is a member of the Rocket Stars, meaning that if open warfare were to break out between Maquise and Rishiri they would be on opposite sides. Interestingly, she joined the Rocket Stars for the same reason Gamaliel joined the Silver Knights: she believes that they are ones most capable of keeping peace among the space colonies.
He has chrome colored cybernetic eyes.